Use Colorbox to display large image

I see two possible solutions:

1) Show image in lightbox when you click on the large image displayed on the right or on a "fullscreen" button or something like that, that's easy to do.

2) Have a mode where instead of the thumbnails panel + large view panel, you only have thumbnails and clicking a thumbnail directly shows it in lightbox. That's not really (or really not) what I intended, but it might be nice. I don't really like the idea of having two rather different interfaces though, and the one I use myself is the current one so I will keep it.

Now if you're asking for how to change things yourself, you could simply use the jQuery lightbox plugin and include a small JS file with only something like $('.galerie-image a').lightBox() in it, that would do the trick.